Published online Apr 26, 2020. doi: 10.12998/wjcc.v8.i8.1414
Peer-review started: December 15, 2019
First decision: January 7, 2020
Revised: March 3, 2020
Accepted: April 15, 2020
Article in press: April 15, 2020
Published online: April 26, 2020
Gallbladder stones are the commonest cause of acute biliary pancreatitis. Despite that most of the stones are expelled spontaneously through the papilla due to their small size; about 20% to 30% of patients with acute biliary pancreatitis will have persistent common bile duct (CBD) stones. Thus, it is important to identify this subset pf patients since they will need endoscopic stone removal. In real clinical practice, the decision to perform an imaging modality for clarifying a suspicion of CBD stone or to proceed directly to endoscopic retrograde cholangiopancreatography (ERCP) because of strong suspicion of CBD stone is mostly based on combinations of clinical, laboratory and ultrasound findings. Many investigators have noted that the probability of CBD stones is higher in the presence of multiple predictors. We characterized clinical, laboratory and radiological parameters which are easily available that can predict the presence of retained CBD stones among patients hospitalized with acute biliary pancreatitis.
The main driver for performing this study was to develop simple bedside score based on easily available parameters that predicts the presence of retained biliary stones, since identification of CBD stone is crucial to relieve biliary obstruction. This score might stratify patients into low or high-risk probability for retained CBD stone and subsequently assist clinicians in performing further confirmatory/therapeutic tests.
Given that retained biliary in the setting of acute biliary pancreatitis required performing certain imaging such as endoscopic ultrasound (EUS) or magnetic resonance cholangiopancreatography (MRCP) which are either invasive or not widely available, we aimed to explore simple easily available clinical, laboratory and imaging parameters that predict CBD stone with good statistical performance.
We performed a single center retrospective case control study including 154 patients with presumed diagnosis of acute biliary pancreatitis who underwent EUS. The strength of our study is that we relied on EUS as a gold standard for the diagnosis of CBD stones, and second that we aimed to combine several parameters to generate scoring system that could predict CBD stone with high probability.
After assessment of several clinical, laboratory and radiological parameters, we were able to identify 3 parameters that were statistically significant on univariate and multivariate regression analysis including age, GGT level and CBD width by US. Using these variables, we generated a score predicting the presence of retained CBD stones. A score that ranges from 51.28 to 73.7 has a very high specificity (90%-100%) for CBD stones, while a low score that ranges from 9.16 to 41.04 has a high sensitivity (82%-100%), as the patients with the higher score might be referred immediately for ERCP without the need for further investigations, while the low score cut-off points might benefit from watch and see strategy or other confirmatory tests for CBD stones.
For the first time, we were able to generate a simple scoring system that predicts the presence of retained CBD stones among patients with acute biliary pancreatitis. Currently, the professional societies including the American Society of Gastrointestinal Endoscopy and the ESGE are relying on individualized predictors of CBD stones. The ability to incorporate several variables into one scoring system further improve the diagnostic accuracy of this score, as is known that combining several predictors for CBD stone is superior to each predictor alone. Thus, our score might be already introduced into the daily clinical practice that guide therapeutic decisions.
The diagnosis of retained CBD stone in acute biliary pancreatitis is somehow challenging as it based on single abnormal laboratory or ultrasonographic tests. However, once a suspicion is raised, most clinicians proceed to other confirmatory tests, mainly EUS which is invasive test or MRCP which is costly and not easily available. However, as we shown that combining predictors for CBD stone into one scoring system had an excellent diagnostic performance. This will allow clinicians to avoid performing other unnecessary imaging studies. Large prospective cohort studies assessing combination of several CBD stone simple predictors are warranted.